#include<iostream> 
#include<cmath>
#include<algorithm>
using namespace std;
const int maxn=1e6;
const double INF=1e100; 
struct node{
	double x,y;
	int flag;
}a[maxn],term[maxn];
bool cmpx(node a,node b)
{
	return a.x<b.x;
}
bool cmpy(node a,node b)
{
	return a.y<b.y;
}
double dist(node a,node b)
{
	return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y));
}
double mindist(int left,int right)
{
	if(left==right)
		return INF;
	if(left+1==right)
	{
		if(a[left].flag==a[right].flag)
			return INF;
		else
			return dist(a[left],a[right]);
	}
	int mid=(left+right)/2;
	double d1=mindist(left,mid);//左区间最小值 
	double d2=mindist(mid+1,right);//右区间最小值 
	double dis=min(d1,d2);
	int i,j,k=0;
	for(i=left;i<=right;i++)
	{
		if(fabs(a[i].x-a[mid].x)<=dis)
			term[k++]=a[i];
	}
	sort(term,term+k,cmpy);
	for(i=0;i<k;i++)
	{
		for(j=i+1;j<k;j++)
		{
			if(term[j].y-term[i].y>dis)
				break;
			if(term[i].flag!=term[j].flag)
				dis=min(dis,dist(term[i],term[j]));
		}
	} 
	return dis;
}
int main()
{
	int t,n;
	scanf("%d",&t);
	while(t--)
	{
		scanf("%d",&n);
		for(int i=0;i<n;i++)
		{
			scanf("%lf%lf",&a[i].x,&a[i].y);
			a[i].flag=0;
		}	
		for(int i=0;i<n;i++)
		{
			scanf("%lf%lf",&a[n+i].x,&a[n+i].y);
			a[n+i].flag=1;
		}
		n*=2; 
		sort(a,a+n,cmpx);
		double ans=mindist(0,n-1);
		printf("%.3lf\n",ans);
	}
	return 0;
}